Saturday, August 27, 2011

The Wake Forest, NC company has taken out a few full-page ads in C&EN: clean, simple black structures on white backgrounds, illustrating the wide variety of oxetane, azetidine, and spiro-heterocycles intended for stitching into med-chem lead molecules. But their latest ad, a portion of which is shown here, takes the cake.

As any Linnaean taxonomist can tell you (*Kings Play Chess On Fat Grey Stools, anyone?), classification runs deep in the scientific blood. When you consider the sheer number of organic molecules that can exist (10^60 potential molecules of 500 MW or less?!), please forgive the namers for getting a little punchy. Molecules garner nicknames based on their appearance (propellanes, cubanes), their smell (putrescine, cadaverine), or other chemists (bullvalene)!

The naming convention for small, 5-membered heterocycles proceeds thusly: start with Latin or English names of the heteroatom, and add "ole" to the end (rhymes with "pole" or "coal," not like Olé!).

Friday, August 26, 2011

I'm interested in how internet memes get started; it's probably the same mob psychology that drives events like Black Friday or stock market bubbles. Either way, when I read Carmen Drahl's Haystack post with the handwritten chemical structures, followed by Chemjobber's homage, I felt the urgent need to actively participate in what is, undoubtedly, the next big thing on the internet: structure drawing!!!

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Perhaps I should link this to a catchy jingle, or a flashing banner ad?

﻿So, there you go, now I'm part of the groundswell. Feel free to comment or critique, I'll even start you off: yes, I know my hydrogens look like "4's", and the persnickety demands of my postdoc advisor for exactness drove my desire to cap off those alkyl stereocenters with an actual group.

Sunday, August 14, 2011

For every occupation, a mark: grass stains on athletes’ socks, tar for roofers’ pants, or grease on mechanics’ smocks. But has Mike Rowe, host of Discovery Channel’s Dirty Jobs, donned a lab coat lately? Synthetic chemists work every day with substances other people use to dissolve metals, dye fabrics, or kill microbes. Naturally, we end up wearing some of it by the end of the day.

R.B. Woodward: Suit or bust!
Credit: nobel.se

A long-standing joke among bench chemists: you can tell a lab visitor straightaway . . . because they wear nice clothes! Looking at pictures of scientists from a few generations ago, one wonders why they chose to dress so sharply for an inherently messy, hands-on occupation: in the days of R.B. Woodward [1965 Chemistry Nobelist], de rigueur lab wear was a 3-piece suit, tie, and (maybe) a smock. Goggles or gloves weren’t strictly required. The counter-cultural ethos of the following scientific generation eschewed formal dress for button-downs, khakis, loafers, and lab coats, a change which may also have been driven by old-timers’ tales of neckties stuck in stirring rotors or acid-eaten sport coats.

Today, synthetic organic chemists just don’t wear really nice clothes, because they won’t stay that way for long. In every corner of the lab lurk wardrobe-destroying substances.

It’s not just appearance under attack: ethanethiol, the odorant most people associate with gasoline pumps or natural gas leaks, leaches into hair and clothes, leaving a persistent sulfuric smell.

Indelible Metals - I once made a bright yellow ruthenium hydride complex, a trace of which spilled on my dark green T-shirt. No matter how many times it’s been through the wash, the compound stays firmly stuck in the fabric. Ditto dark orange stains from nickel complexes set into my white lab coat. Khaki pants develop purple-brown stains from silver complexes or iodine. Perhaps spills like these gave chemical company Johnson Matthey the idea for FibreCats, catalytic metals immobilized on fibrous strands for easy recovery.

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Much closer to real life!
Credit: test-tube.org.uk

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Scorched Shirts – Ever spill concentrated sulfuric acid on cotton? You won’t know until the spray-pattern of tiny holes shows up after washing and drying on high heat. Since cellulose and sucrose are both sugar-based, perhaps this is the clothing equivalent to the black carbon snake general chemistry demo. Be especially careful with that bottle of nitric acid; one of the first synthetic explosives, nitrocellulose or “gun-cotton,” was made accidentally in the early 1800s as cloths used to clean up spills would explode suddenly when left to dry.

Some pertinent advice for those who wish to look good in lab? Find a good dry cleaner.

Thursday, August 11, 2011

﻿﻿(A few weeks back, I posted about rare earth chemistry, and how insufficient domestic supply may hurt new-tech industries in the US. Prof. Eric Schelter, a Professor of Inorganic and Materials Chemistry, graciously spoke with me about his research) ﻿﻿﻿﻿

SAO: How did you become interested in inorganic / organometallic chemistry, and rare earth / actinide chemistry specifically?

﻿﻿﻿﻿ES: I became interested in inorganic chemistry through interaction with my excellent undergrad mentor, Prof. Rudy Luck at Michigan Tech. Rudy set me up with a synthetic project on a dihydrogen complex of rhenium. This experience was quite formative as Rudy also got me interested in Texas A&M for grad school (he was a postdoc at TAMU). Also, the exposure to dihydrogen complexes introduced me to Los Alamos National Laboratory through the work of Greg Kubas.

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In grad school at TAMU I did more synthesis and worked on electronic structure with Kim Dunbar. Working with Kim and her group was a great experience to learn X-ray crystallography, magnetism and electrochemistry. I had an interest in working with actinides so I pursued the LANL postdoc where I learned some uranium and thorium chemistry with Jackie Kiplinger and lanthanide chemistry with Kevin John. My interests in magnetism and f-block chemistry dovetailed nicely for starting my independent career in rare earths and energy science at Penn.

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Prof. Eric Schelter (credit: UPenn)

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SAO: We've read in National Geographic and Discover about rare earth usage in smartphones, hybrid cars, and military applications. Can you give examples of other industries that rely heavily on these metals?

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﻿ES: In general, rare earth magnetic materials are very important in many industries. Rare earth (RE) permanent magnets, primarily NdFeB, are used in the wind energy industry in large capacity turbine generators. The permanent magnets are also used in hard drives. Fluorescent lighting depends on phosphor materials that contain REs, especially europium and terbium. Neodymium is also used is lasers. Lanthanum and cerium are important catalysts in FCC [Fluid catalytic cracking]petroleum refining. Erbium is used in amplifiers for fiber optic communication. Yttrium is a critical component of high temperature superconducting materials. Gadolinium has an important use in medicine as a contrast agent in magnetic resonance imaging. This is by no means an exhaustive list.﻿﻿﻿﻿

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SAO: Given the supply problem (the US currently does not produce enough rare earths for domestic industry), what is our long-term strategy to obtain more? Do we have a reserve, like the Strategic Petroleum Reserve, that we can operate from? Or will new mining and separation techniques be the answer?

﻿﻿﻿﻿ES: There is currently no comprehensive long term strategy to address the US supply crisis and no strategic reserve of REs. A single supplier (Molycorp) of REs exists in the US, but rare earths are not rare - there are reserves of light and heavy rare earths in many places in the lower 48 [states] and in Alaska. There is a great opportunity here for scientists to help meet an important need by improving methods of obtaining pure RE materials.﻿﻿﻿﻿﻿﻿

SAO: How does your research address the rare earth supply problem?

﻿﻿﻿﻿﻿﻿ES: Much of the cost, time, and energy in obtaining rare earths is concentrated at the separations stage. We're working on new separations chemistry from several angles. In work sponsored by the DOE we're developing a new extractant strategy for use in liquid-liquid separations. We expect to contribute to a renewed domestic supply chain by targeting certain high value REs and improving the efficiency and reducing the environmental impact of their separations. We are also exploring fundamental redox chemistry of REs for application to separations.﻿﻿﻿﻿

﻿﻿﻿﻿ES: I am a complete /Lord of the Rings /enthusiast (freak) and am anxiously awaiting the film release of The Hobbit: An Unexpected Journey (SAO: Me too!)﻿﻿

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Wow, much thanks to Prof. Eric Schelter for his preparation and willingness to be interviewed. Readers, if you (or someone you know) on the cutting-edge of chemistry would like to be interviewed, simply leave a comment here or contact me at seearroh_at_gmail.com

See Arr Oh

Who is this masked chemist?

Finding my way through new challenges.
I was a founding blogger at Scientific American's Food Matters and Blog Syn. I once wrote for C&EN's The Haystack. I've written for Nature Chemistry, Newscripts, Chemistry Blog, Chemjobber, and Totally Synthetic.